AB1584-PARE UNDERSTANDING HETEROGENEITY IN PATIENTS’ CONCEPTUALIZATION OF TREATMENT FOR RHEUMATOID ARTHRITIS: A CLUSTER ANALYSIS
Authors: B. Hsiao, J. Downs, M. Lanyon, J. R. Curtis, S. Blalock, C. Wiedmeyer, S. Venkatachalam, W. B. Nowell, L. Fraenkel
Journal: Annals of the Rheumatic Diseases (2022)

Background Uptake of treat to target strategies for the management of rheumatoid arthritis (RA) is low. System-related barriers to accessing treatment are known, but poor adherence to starting and continuing treatment are prevalent causes of suboptimal care. Objectives To better understand heterogeneity in patients’ conceptualization of RA treatment to inform interventions aimed at improving appropriate utilization of disease modifying antirheumatic drugs (DMARDs). Methods Participants (pts) were recruited from the ArthritisPower US online research registry. Pts who met eligibility criteria [physician diagnosed RA currently being treated with DMARD(s)] rated 56 items (coded on 5-point scales) reflecting concepts raised during in-depth patient interviews. To combine similar items for ease of analysis and interpretation, we conducted a principal components analysis using Varimax rotation. We then entered mean scores, weighted by how heavily each item loaded onto each factor, into a k-means cluster analysis. We examined whether demographic characteristics differed across clusters using ANOVA for continuous and chi-square for categorical variables. Results Pts (N= 621) ranged in age from 22 to 93, with a mean of 57 years (SD= 11.5). Most (89%) were female and reported as non-Hispanic white (89%); 27% reported having a post-graduate degree. A scree plot revealed that a 4-factor solution explaining 36.8% of the variance would provide desirable interpretability, with a discontinuous drop in eigenvalues for additional factors slowly tapering and adding little discriminability between later solutions. The four factors (% variance explained, number of items) were: 1) Access to high quality care and support (12.10%, n= 21); 2) Comfortable adding/switching DMARDs (9.73%, n= 14); 3) Perceived favorable DMARD risk/benefit ratio (8.74%, n= 15); and 4) Confidence that testing reflects disease activity (6.20%, n= 6). A 5-cluster solution showed the most stable convergence of cluster centers after 10 iterations. Figure 1 shows the weighted mean scores for each factor across clusters. The largest group (31.7%) is characterized by mean scores on each of the four factors toward the high end of mean responses for the sample, reflecting positive experiences; we labeled this group “Successfully Engaged in Care” to indicate a positive rheumatologist relationship, feeling well-informed and active participation in care. The next group (24.3%) also had high scores for Factor 1 (access to high quality care/support) and Factor 3 (perceived favorable DMARD risk/benefit ratio), but were less comfortable adding/switching DMARDs (Factor 2) and had less confidence in testing reflecting their disease activity (Factor 4); we labeled this group “Worried About Medication”. The three remaining clusters are smaller. The third cluster (16.4%), labeled “Skeptical of Testing,” had a favorable view of DMARDs (Factor 3) despite lower scores related to access and quality of care (Factor 1) and confidence in testing (Factor 4). The fourth cluster (14.3%) expressed low perceived value of DMARDs as well as reduced scores for DMARD risk/benefit and confidence in testing; we labeled this group “Resistant to DMARDs.” The last cluster (13.2%) scored lowest on their rating of access to high quality care and support, indicating less access to, and satisfaction with, information needed to support decision making. Their perceived risk/benefit ratio for DMARDs was still favorable, so we labeled this group “Dissatisfied with Care.” Conclusion Patients’ conceptualization of RA treatment varies, but discomfort with adding/switching DMARDs appears to be ubiquitous regardless of perceived benefits associated with DMARDs and access to high quality care/support. Interventions outside of the traditional physician-patient relationship are needed to facilitate treatment escalation in patients with RA. Further research is required to understand residual variance not explained by our model. Acknowledgements The authors thank the patients for their participation. Disclosure of Interests Betty Hsiao: None declared, Julie Downs: None declared, Mandy Lanyon: None declared, Jeffrey R. Curtis Consultant of: Gilead, Novartis, and Samsung, Grant/research support from: AbbVie, Amgen, BMS, Corrona, Eli Lilly and Company, Janssen, Myriad, Pfizer, Regeneron, Roche, and UCB, Susan Blalock: None declared, Carole Wiedmeyer: None declared, Shilpa Venkatachalam: None declared, W. Benjamin Nowell Grant/research support from: •William B. Nowell is the Principal Investigator on grants/contracts from AbbVie, Eli Lilly and Company, and PCORI, and an employee of the Global Healthy Living Foundation (GHLF). GHLF receives grants, sponsorships and contracts from pharmaceutical manufacturers and private foundations. A full list of GHLF funders is publicly available here: https://www.ghlf.org/our-partners/ ., Liana Fraenkel: None declared